JERUSALEM 
An Israeli airstrike killed a Gaza militant Friday as he was preparing to launch rockets, Israel's military said, the latest casualty in a week-long exchange of cross-border attacks.

Violence erupted Monday when two gunmen infiltrated into Israel along its border with Egypt's Sinai peninsula and killed an Israeli Arab construction worker who was on a crew building a security fence meant to avert such attacks. A little known al-Qaida-inspired group, the Mujahedeen Shura Council of Jerusalem, claimed responsibility and identified the gunmen as an Egyptian and a Saudi.

Since then, Palestinian militants in Gaza have according to the Israeli military's count fired over 130 rockets at Israel injuring several people, spreading panic and damaging apartment buildings. Israeli retaliatory airstrikes on Gaza militant targets have killed at least 6 Palestinians.

The flare-up is the most serious in months, drawing in militants from Hamas, which rules the territory but has largely refrained from attacking Israel since a war more than three years ago. Other Palestinian groups persisted with rocket assaults and other attacks on Israel during that time.

Gaza health official Ashraf Al Kedra confirmed a death and an injury from the Friday strike.

"Aircraft targeted a terrorist squad during preparations to fire a rocket at Israel from the central Gaza Strip," the Israeli military said. It said it holds Hamas accountable for any attacks originating from the Gaza strip.

No militant group claimed the dead man as a member. Witnesses said that the mourning at his funeral later in the day - the black flag on the coffin, and the absence of any chants connected to other factions - indicated that he belonged to an ultraconservative Salafi group inspired by al-Qaida, like the group that carried out Monday's attack. They spoke anonymously so as not to get involved.

Also Friday, Israeli police said they were investigating graffiti found scrawled in Arabic on a synagogue in northern Israel.

Police spokesman Micky Rosenfeld says the phrase, "There is no god but God," was sprayed on the outside of the synagogue in Moshav Maor.

The vandalism comes days after a mosque in the West Bank was torched and vandalized with Hebrew-language graffiti protesting the Israeli government's upcoming evacuation of a Jewish outpost in the area.